Heavy media hydrocyclones in mineral beneficiation

The paper reviews some of the important works on the use of dense media suspensions in hydrocyclones to effect separation between minerals on the basis of their specific gravities. A favourable case has been presented to justify a discussion on the topic by enumerating the outstanding advantages of the system. A brief mention has been made of the elementary principles regarding the working of the heavy media hydrocyclones to facilitate the discussions that follow. The effective escape space available to the inflowing slurry is of paramount importance in controlling the operation of the system and hence, the volume of throughout, rather than its weight, is of significance in controlling the performance of the machine. The introduction of a heavy medium interferes with the natural classifying action of the hydrocyclone and brings about a split amongst the mineral particles on the basis of their densities, rather than their masses, thereby minimising the influence of particle size. Conclusions, useful for the selection of machines for the selection of machines for specific purposes and their operational control have been drawn from the findings of the various works. Special mention has been made of the effect of viscosity of media on the separation characteristics and possible means of controlling it. Suggestions have been made on the possibilities of further work in the field. (Shri D.M. Chakrabarti, Scientist, National Metallurgical Laboratory